Optical glass with high refractive index and high dispersion serves as the extremely significant part of the optical instruments and photoelectric products. With the widespread of photoelectric products such as smart phone and SLR camera in recent years, higher requirements have been proposed for the performance of this type of optical glass, which means to reduce its Pg, F to better improve the chromatic aberration so as to enhance the imaging quality of the optical lens.
Among the currently known optical glasses which are of high refractive index and high dispersion and adopt SiO2—TiO2—Nb2O5—Na2O—BaO system, plenty of TiO2 can be found in the glass system disclosed by CN1915875B, which not only degrades the transmittance of the glasses but can also increase the Pg, F in the glasses. The optical glass disclosed by JP S48-034913 adopts SiO2—TiO2—Nb2O5—K2O (Na2O) system which shows the problem of high Tg and high Pg, F. Glasses disclosed by JP2004-161598 is easy to encounter the problem of devitrification, and expensive component of GeO2 may probably involve in the components, which makes the glass price tend to be high and is not conducive to the industrialization production.